Simplify the following expression: $a = \dfrac{5}{z + 1} \times \dfrac{7z}{5}$
Solution: When multiplying fractions, we multiply the numerators and the denominators. $a = \dfrac{ 5 \times 7z } { (z + 1) \times 5}$ $a = \dfrac{35z}{5z + 5}$ Simplify: $a = \dfrac{7z}{z + 1}$